1. Field of the Invention
The invention relates to an architectural covering, particularly a covering for an architectural opening such as a window blind, having two parallel interconnected fabric layers which contain complementary patterns and can be moved relative to one another in a direction parallel to the layers. This invention particularly relates to an architectural covering having one or more parallel binder threads which connect the fabric layers and along which one of the layers can be moved relative to the other layer. This invention quite particularly relates to an architectural covering having fabric layers which contain alternating relatively translucent and relatively opaque portions and can be moved relative to one another between positions where: i) the translucent portions of the different layers coincide and ii) the opaque portions of the different layers substantially overlap, preferably completely overlap, the translucent portions of the different layers.
2. Description of the Relevant Art
Blinds for covering architectural openings are known which can be opened and closed while still covering the openings. For instance, traditional Venetian blinds have slats which can be tilted so as to block light or let light through from windows covered by the blinds.
Another type of such blind has two vertical layers, disposed one in front of the other and each with an array of horizontally-oriented, alternating transparent and opaque stripes. When the transparent stripes of one layer are in horizontal alignment with the transparent stripes of the other layer, light is transmitted through the blind, but when the opaque stripes of one layer are horizontally aligned with the transparent stripes of the other layer, light can be blocked by this blind. See GB 926 663, GB 1 227 619, U.S. Pat. Nos. 2,029,675, 2,549,167, FR 1 366 224 and DE 2 326 438. The two layers of fabric or plastic in such a blind are connected on their top and/or bottom ends by top and/or bottom bars. This generally results in the layers being separated by the diameter of the bars used, which makes the blind appear bulky. Also the distance, separating the two layers, does not allow the blind to completely block light from passing through it. In this regard, light shining in from a window at an acute angle can pass through the transparent stripes of the adjacent layer of the blind and then between the vertically adjacent, opaque stripes of its layers, in the horizontal gap between the layers. The bigger the horizontal gap between the layers, the more light can pass through, even if the blind is closed. Moreover since the layers in such a blind are connected only at their top and/or bottom, precisely aligning their transparent and opaque stripes to completely close the blind is not possible.
Two-layer woven fabrics are also known which are interconnected by binder threads, so that they have a special appearance and resistance to wear and tear. See, for example, U.S. Pat. No. 2,502,101, FR 2 063535, GB 2 058 161, U.S. Pat. No. 4,025,684, GB 395 176, U.S. Pat. No. 3,359,610, GB 540 059, NL 35 856, NL 272 858 and U.S. Pat. No. 3,943,980. However, the two layers of such a fabric cannot slide along the binder threads or move relative to one other.